We had the opportunity to replace the clutch in a 2006 Dodge 3500 equipped with a Cummins and the G56 six-speed transmission. This "old" truck has seen some use, with around 365,000 miles on it. It was used for hauling RV's across the States in its first life and then sold at auction. The new owner graciously offered us the chance to swap the clutch out for him. We'll tell you what you need to know to do this yourself.
New South Bend Clutch OFE (performance organic / feramic) clutch plate. The performance organic material shown facing up.
New South Bend Clutch pressure plate.
If you're like us, you hate to tear into something and do the work if you're just going to put stock parts back into it. We think that if we're going to go to the trouble, we should use upgraded parts whenever we can. We chose to install a South Bend OFE clutch and solid flywheel for this project. The owner of the truck was going to make moderate power upgrades, such as software, intake, and exhaust, so we chose an OFE clutch for the application. An OFE clutch has performance organic clutch lining on one side of the clutch and feramic (sintered iron) lining on the other side. This offers smooth engagement as the performance organic side contacts the pressure plate, and heavy duty engagement as the feramic side contacts the flywheel. It's a great general purpose clutch that will withstand some abuse on a modified diesel, but still offers great drivability and economy when compared to a stock clutch. The flywheel we are using with the clutch is leaps and bounds better than the stock dual-mass flywheel that came in the truck. The OEM dual-mass flywheel is much like a flex plate used in an automatic transmission with a thicker metal ring bolted to it. It has springs built into it to dampen transmission gear lash. Gear lash is noise that can be heard from the gears in the transmission as the engine's rotational force rattles the transmission gears back and forth. This is mostly noticeable when the truck is in neutral with the clutch engaged. The South Bend flywheel is one solid piece of steel that's been cryogenically frozen to keep the molecules in the metal uniform, in order to keep the disc true and flat under heat and stress. We'll also be installing a new clutch hydraulics kit from South Bend Clutch because the stock hydraulics usually won't have enough pressure to fully disengage the firmer springs in the South Bend pressure plate.
First, start by draining the fluid from the transfer case and transmission into a clean container. Depending on the interval of the last fluid change and the service life your transmission has, you may be able to reuse it.
Next, remove the front and rear drivelines from the transfer case.
Unbolt the transmission mounts from the crossmember. The crossmember has holes on the bottom side to access the bolts.
Remove the plastic surrounding the shifter, shift boots, and shifter from the top of the transmission. This is also where the transmission should be filled with fluid after it's installed.
Unbolt the exhaust mount from the side of the bell housing.
Remove the hydraulic slave cylinder and wiring harness from the transmission.
Remove the crossmember from under the transmission.
Unbolt and remove the transfer case from the transmission.
shifter mounts on top of the transmission. Shown from inside the cab.
Exhaust mount on the passenger side of the transmission bell housing.
OEM Slave cylinder on the driver's side of the transmission.
It's helpful to have someone help you remove the transfer case and transmission. They're heavy and if you're attempting the removal and installation by yourself, without a good transmission jack, there's a good chance it could fall and either cave your chest in or squash your head.
After the transfer case has been removed, loosen the bell housing bolts that hold the bell housing to the engine block. Before the bolts are removed, secure the transmission safely on a transmission jack. After the transmission is secure, remove the bolts, slide the transmission backwards until the input shaft is free from the clutch and lower it down to the floor.
Remove the 8 bolts that hold the pressure plate to the flywheel. Remove the pressure plate and clutch plate that sits directly behind the pressure plate.
8 bolts mounting OEM pressure plate to the flywheel. Access cover to remove OEM flywheel mounting bolts.
After the pressure plate and clutch have been removed, open the access cover on the engine side of the back of the block. This cover is to access the torque converter bolts on trucks with automatic transmissions and also to access the bolts that hold the flywheel ring to the "flex plate" type mass of the flywheel. The bolts holding the outer ring of the flywheel can now be removed through the access hole. Remove the outer flywheel ring.
Access cover to remove OEM flywheel mounting bolts.
Next, unbolt the inner mass of the flywheel from the engine crankshaft and remove the flywheel completely.
Dual-mass flywheel after the outer mass has been removed.
Now the crankshaft and rear main engine seal can be seen. It looks like it's leaking a little, so we'll go ahead and replace it while we're here. Use a couple of angled picks to get a hold of the seal from the outer edges and work it out from around the crankshaft. Take care not to pick at the seal from the crankshaft surface to avoid scratching where the seal will ride on the crankshaft surface.
Rear main seal with slight oil leak.
It's important that the new crankshaft seal be completely dry as we install it. There can be no oil on the sealing surfaces of the seal when we install it. If oil is between the seal and the crankshaft, it will not allow it to seal properly and the seal will leak prematurely.
The new rear main seal should come with a metal ring that is used to tap the seal in place evenly and at the correct depth around the crankshaft. Place the new seal over the crankshaft. With the metal installation ring over the seal, tap the ring gently with a hammer evenly, until the ring is seated against the rear main seal bracket that's mounted to the back of the engine block.
New rear main seal installed on the crankshaft.
Next, attach the new flywheel to the crankshaft with 8 new bolts. Use red thread lock on the bolts. Torque the bolts to the manufacturer's specification, ensuring that the flywheel mounts flat against the crankshaft. The new flywheel came from South Bend Clutch with the pilot bearing pressed into it.
South Bend flywheel bolted to the crankshaft.
Using the plastic clutch alignment tool that came with the kit, place the new clutch in position against the flywheel. It's important that the flywheel, clutch disc, and pressure plate remain absolutely clean and free of oil or other contaminants as they are installed.
Use the clutch alignment tool to position the clutch plate with the flywheel while mounting the pressure plate.
With the clutch alignment tool in place, bolt the new pressure plate to the flywheel using the supplied bolts and red thread lock. Bolt the pressure plate on evenly, using a star pattern and tightening them incrementally. Torque the bolts using the manufacturer's specification. After the pressure plate is bolted into place, it will hold the clutch disc in place, so the clutch alignment tool can be removed.
South Bend pressure plate installed over the clutch disc.
Next, remove the old throw out bearing from the input shaft of the transmission by removing the retaining springs from where they clip to the clutch fork. Apply grease to the surface of the new throw out bearing where it meets the input shaft and install it on the shaft, attaching the springs on the new bearing to the clutch fork.
If you suspect any issues with your transmission, such as excessive play in the shifter or gears, sluggish shifts, sticky or show shifts, this would be a great time to inspect the internals of the transmission. It's a good idea to have a transmission shop look at it if don't have experience diagnosing a transmission. Potential problems can be diagnosed early by an experienced eye, which will save you money and headache in the future.
New throw-out bearing installed on the OEM clutch fork.
Put the transmission back on the jack and install the transmission and other components in the reverse order you took them out. Don't forget to fill the transmission and transfer case up with fluid before you drive!
We recommend over filling the G56 and especially the NV5600 transmissions up to one additional quart after the fluid has reached the full level. The full level is reached after fluid spills from the plug on the passenger side of the transmission.
South Bend Clutch